Answer:
Explanation:
Translation:
- <em>What volume will 12g of iron occupy?</em>
<em></em>
<h2>Solution</h2>
<em />
<em>Iron</em> is a solid substance at room temperature. You can find the <em>volume</em> of solids (and of not solids) using the density.
You can obtaindthe density of most pure substances in the internet. The density of<em> iron</em> at room temperature is 7.874 g/cm³.
Thus, substituting in the formula, you get:
The answer is rounded to two significant figures because the input, 12g, has two significant figures.
Answer:
2 Al + 3 Pb(NO3)2 > 2 Al(NO3)3 + 3 Pb
Explanation:
To solve this, we can use two equations.
t1/2 = ln 2 / λ = 0.693 / λ
where, t1/2 is half-life and λ is the decay constant.
t1/2 = 10 min = 0.693 / λ
Hence, λ = 0.693 / 10 min - (1)
Nt = Nο e∧(-λt)
Nt = amount of atoms at t =t time
Nο= initial amount of atoms
t = time taken
by rearranging the equation,
Nt/Nο = e∧(-λt) - (2)
From (1) and (2),
Nt/Nο = e∧(-(0.693 / 10 min) x 20 min)
Nt/Nο = 0.2500
Percentage of remaining nuclei = (nuclei at t time / initial nuclei) x 100%
= (Nt/Nο ) x 100%
= 0.2500 x 100%
= 25.00%
Hence, Percentage of remaining nuclei is 25.00%
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